It is praise/worship and study the bible...Everybody eat lunch (Join them if you choose to, am sure you will love to) and go home. It is as simple as that

Am not sure i know of any English speaking catholic church in Danang, maybe Hanoi or Saigon. I know of Hanoi, not sure of Saigon.

Also a local church in Da nang (http://dananghoianexpats.com/content/hoa-my-church) have some translators that help translate Vietnamese to English when foreigners are present. So if it is fine with you to have an headphone on while someone helps translate in clear English, you can also attend Hoa My Church as well.

These are the churches am familiar with...Not sure if anybody wants to sure with you .....